PDF Watermark Online Free — Add Text or Image Watermark
Protect and brand your PDF documents with professional watermarks. Add text stamps like CONFIDENTIAL, DRAFT, or SAMPLE with full control over font, size, color, opacity, rotation angle, and position. Or upload a logo image for a brand watermark. Apply to all pages, odd/even pages, or a custom page range. Live preview shows the result before you download. Powered by pdf-lib — runs entirely in your browser.
100% private. PDFs are processed locally using pdf-lib in your browser. Nothing is uploaded to any server.
How to Add a Watermark to a PDF Online Free
- 01
Upload your PDF
Drop any PDF up to 20 MB. Page thumbnails are shown as a preview.
- 02
Configure watermark
Choose Text or Image watermark. Set text content, font, color, opacity, rotation, and position. Live preview updates as you type.
- 03
Download watermarked PDF
Select which pages to watermark, then click Download. Your watermarked PDF is ready instantly.
Frequently Asked Questions
What text watermarks can I add to a PDF?
You can type any text into the watermark field — common choices are CONFIDENTIAL, DRAFT, SAMPLE, INTERNAL, or a company name. Quick-fill buttons are provided for the most common labels. You can customize the font (Arial, Times New Roman, or Courier), size (20–200px), color, opacity, rotation angle, and choose between centered or tiled placement.
Can I add a logo or image as a watermark?
Yes. Switch to the "Image" tab and upload any image file (PNG with transparency works best for a professional look). Choose from small, medium, large, or a custom percentage of the page size. Position it using the 9-point grid (top-left, center, bottom-right, etc.) and control opacity independently.
How do I make a diagonal CONFIDENTIAL watermark?
In the Text tab, set the text to "CONFIDENTIAL", set the rotation to -45°, set the opacity to around 20–30%, and choose the "Center" position. This creates the classic diagonal stamp effect seen in professional documents. You can also use "Tile" to repeat the watermark across all pages.
Can I watermark only odd or even pages?
Yes. The "Apply to pages" selector lets you apply the watermark to all pages, odd pages only, even pages only, or a custom page range (e.g., pages 2 to 10). This is useful for watermarking only the content pages while leaving the cover or appendix pages clean.
Is my PDF uploaded to a server?
No. The entire watermark operation is performed in your browser using pdf-lib, a pure JavaScript PDF library. Your file is loaded via the FileReader API and the watermarked PDF is generated and downloaded client-side. No file ever leaves your device.